Typical mobile telephone units, both cellular and PCS, include a keypad and an LCD display for the user interface. The user of the mobile unit controls the operation of the telephone through the user interface, entering commands, characters, and phone numbers with the keypad. The user then views the commands entered and other information on the display. To facilitate the use of the keypad and display while the mobile telephone is operated in the dark, or in areas having limited ambient light, the display and keypad is often back-lighted.
The size of a mobile phone generally limits the size of the display, which in turn limits the amount of information that can be visually presented on the display at one time. The portion of the face of the telephone that is used for the display varies depending on the type of display and keypad. A common example of a mobile phone configuration has a liquid crystal display (LCD) having one to four lines capable of displaying text, each line having multiple character positions composed of a dot matrix. The dot matrix can also be used to display graphic images. A portion of the remaining area of the phone is occupied by the keypad. The keypad contains an array of individual push-buttons, or "keys", which are used for either a fixed function or a soft function. A fixed function key has a single function, regardless of the actual configuration or status of the telephone. A soft function key is a key which is dynamically assigned a variety of functions from a pre-determined set of functions. Most fixed function keys will have some type of lettering or symbology which indicates its function. A soft function is usually marked to identify its dynamic functionality.
An example of a mobile phone having a display and keypad configuration is disclosed in U.S. Pat. No. 5,425,077 of Tsoi (issued on Jun. 12, 1995) for an invention entitled "Mobile Telephone User Interface Including Fixed and Dynamic Function Keys and Method of Using Same." In the configuration disclosed by Tsoi, much of the front surface of the telephone is used for the display, and the control of the telephone is achieved using an array of soft-function keys.
FIG. 1 illustrates another example of a prior art telephone display and keypad configuration commercially known as the Nokia Model 2120. Referring to FIG. 1, the prior art telephone is shown and generally designated 100. Telephone 100 includes display 102, keypad 104, microphone 106, speaker 108, antenna 110, a speaker volume adjustment 112. The telephone is turned on by pressing ON/OFF button 114, which provides power to the telephone which in turn runs through its power-on testing sequence. Once the testing sequence has been completed, the telephone is ready for use.
Display 102 is formed with textual display areas 116, 118, 124, 126, 128 and graphical display areas 120, 122. In addition, cursor 130 is provided to allow the user to identify any selection from the menu by moving the cursor 130 from its initial position to alternative positions 132 and 134 within display 102. Graphical display areas 120 and 122 are used to provide easy identification of the remaining battery life and the radio frequency signal strength.
The keypad 104 includes a pair of soft keys 138 and 140, and a cursor movement key, or indexing key, 136. These three keys 136, 138, and 140 allow the user to move through the complicated menu scheme by pressing soft key 140 to select the menu, then moving the cursor 130 within that menu using the indexing key 136 and selecting a particular menu entry by pressing the other soft key 138. Keypad 104 also has the standard 10-key alpha-numeric keys such as keys 150, 152, 154, and 156, with the ABC, or alpha, key 144 allowing the user to enter alphanumeric characters. Also, a CLR key 142 is provided for correction of an erroneously entered key or command. A telephone number may be entered and SND key 146 is pressed to initiate a telephone call, and END key 148 is pressed to terminate the call.
Display 102 of telephone 100 shows a menu selection of the mode of the telephone, including an ANALOG mode shown in display area 126, a DIGITAL mode shown in display area 128, and a BOTH mode which incorporates both the analog and digital modes shown in display area 124. In making the mode selection, cursor 130 may be moved from its original position to alternative positions 132 or 134 using indexing key 136. Once the cursor is positioned within the desired display area, such as display area 124, soft key 138 which corresponds to display area 116, currently showing the word "OK", is pressed thereby selecting the "BOTH" mode. Navigation through the various menu commands is often difficult, particularly when there are several levels of menu options in a nested, or hierarchical configuration. While it is possible to successfully operate the telephone using the written manual as a guide, this method of operation if often frustrating and time consuming.
The prior art telephone includes a number of fixed function keys and soft function keys. The fixed function keys are labeled descriptively with their respective functions, such as "SND" for sending a signal, "CLR" for clearing an input signal, and "PWR" for controlling the power to the telephone. The soft function keys are labeled with numbers, letters, or both since their function will be dynamic. In the Nokia telephone, most keys are made from material that is at least partially translucent so that lighting from the underside of the key will pass through to the top side and back light the labeling or marking on the upper surface of the key. Alternatively, the keys can be opaque, with the light being transmitted through the spaces between a key and the face plate, creating a halo around the key. Aside from simultaneous illumination of the markings on all keys, there is no functional information presented by or within the keypad area since most mobile phones typically provide indications of the functions, status or state of the telephone only within the display portion of the telephone.
A data processor, such as a microprocessor, is commonly used to process the inputs from the keypad and generate character or graphic information that is output on the display. This microprocessor is programmed to implement a particular menu structure within which the user can select functions, parameters or modes from a hierarchy of options. To select an option, the user will press a key to present the first level of menu options on the display, for example, a "menu" key. The user then views the available selections in the first level of options by pressing a key, for example, a "scroll" key, or an "up" and "down" key, causing a series of menu options to be sequentially displayed on the display. The option can then be selected by pressing another key, for example, a "store" key or "select" key. Many selection options will have a second level from which the user may choose. For example, a first level menu option selection of "ring volume" would lead to a second level selection wherein the user selects the ring volume desired from a list of ring volumes, for example, from the choices "1," "2," "3," "4" and "5."
Another example of a menu function is "keyguard" which, when activated, partially disables the keypad to prevent inadvertent key-presses from initiating any action or needlessly filling the display with numbers. In order to deactivate the "keyguard" function, the user presses a certain sequence of keys, for example the "menu" key followed by the "*" (star) key.
Due to the large number of menu options and specific key sequences necessary for performing the many functions available in the modern mobile phones, users frequently have difficulty determining which keys need to be pressed in order to achieve the desired operation. In some cases, the display will instruct as to which key should be pressed, but in other cases, there is no such instruction provided. Where no instruction is provided, the user must experiment and possibly initiate an action that was not intended, or refer to complicated and lengthy written instructions for operation of the phone. This may result in frustration to the user, or an inadvertent action being initiated at a cost to the user.
In addition to the failure of existing user interfaces to assist the user of the telephone in its proper operation, the difficulty increases when a phone user attempts to operate the telephone in the dark because the keypad is rarely lighted in a manner which will allow the user to view all keys which are available. Moreover, even if all keys are available, the user must still determine which key provides the appropriate response to a menu selection or other function of the telephone.
In view of the failure of existing user interfaces to provide for easy access to keypad-activated functions in mobile telephone, an improved user interface is needed to facilitate the quick, reliable, and more accurate operation of the phone.